The provision of a ready supply of drinking water is a necessity in the rearing of animals. Smaller animals are typically enclosed in cages, small pens or boxed enclosures. For example, mice and rats are often reared under controlled conditions by maintaining the animals in rearing containers that are essentially plastic boxes. Infant or juvenile rodents are usually nursed by the mother and then weaned to feeding and drinking on their own. During the growth period, the height of mouse and rat mouths, as measured from the floor of the box, do not significantly increase. Such animals are also capable of rearing up on their hind legs to reach a water supply, which is most often an inverted bottle and a descending tube from which a drink may be taken.
Poultry rearing, however, presents a problem since newly hatched chicks do not take nourishment or water from the mother but are able to eat solid food and drink water from the moment they leave the egg. Thus, a readily available water supply must be constantly provided. It is well known in the art, therefore, to install in poultry rearing cages or containers a device such as a gravity valve liquid delivery head connected to a water source. For this type of device to function, the bird must typically push upwards a protruding extension of the valve, thereby opening the valve and delivering water until the bird releases the pressure on the valve. Gravity then causes the valve to descend, cutting off the liquid flow. Since the valve operates by gravity, the bird must place it's beak under the liquid delivery head to push the valve upwards. However, growth of the chicks will quickly mean that a drinking valve at a height suitable for use by newly hatched or young chicks will become too low for older birds to easily operate. At best, the birds will have to strain to reach the valve, or even crouch to place their beaks below the delivery heads.
It is necessary, therefore, to regularly adjust the height of the water delivery heads to accommodate the growing birds, and to lower the drinking units when a fresh batch of chicks is introduced to the cages. Cage rearing of poultry can involve multiple cage units, each of which must have the drinking supply adjusted, which is a labor and cost intensive activity. A variety of adjustable drinking systems have been developed requiring different degrees of labor input. In addition, many of these apparatus are structured in such a way that they may harbor waste or infections contaminant material that may be difficult to access for removal, an essential requirement to prevent potentially devastating infections of flocks.
Adjustable height watering devices include such as U.S. Pat. Nos. 4,724,797 and 4,884,528 to Steudler, Jr. consisting of a liquid delivery head or nipple directly attached to a water supply pipe wherein the entire pipe may be height adjusted by a rapid release hook or the delivery head is rigidly attached to the cage or container. Another example, as described in U.S. Pat. No. 5,765,506 to Hawk & Cron, comprises a waterer fed from a supply tube. Channels in the waterer slideably engage with the bars of a cage to permit elevation of the waterer as the birds grow. This example of a poultry watering system required that it be mounted onto parallel cage bars and not on other models of rearing container. U.S. Pat. No. 5,765,506 to Hawk & Cron, further disclosed a watering device wherein drinking heads or nipples are mounted to a moveable frame that may be automatically height adjusted by a wire and pulley system driven by a motor. This system incorporates a complex mechanism for driving the upward or downward movement of the frame and drinking heads that does not accommodate to a box-like bird container nor easily cleanable.
What is still needed, therefore, is a liquid delivery system for caged growing animals that can be readily adjusted for the increase in height of the birds with reduced labor input, which obviates the labor intensive current practice of detaching each water delivery head from the bird container and reattaching it at a higher position more convenient for the birds. What is also needed is an adjustable liquid delivery system that may be used on a variety of animal rearing containers, of simple construction that may be dismantled for cleaning.